I. Field of the Invention
The invention relates to clamping devices and, more particularly, to clamps having quickly adjustable parts, in which the clamp has a threaded spindle within a threaded bore allowing adjustment of the spindle to a position adjacent the workpiece for clamping.
II. Description of the Prior Art
In general, clamping devices and, more particularly, quick-acting assemblies for clamping members are known in the art. For examples, see U.S. Pat. Nos. 4,582,307; 4,220,322; 4,436,294; 4,185,811; 3,893,813; 3,357,698; 2,768,664; 2,546,336; 2,565,965; 2,156,195; 1,716,887; 1,262,300; 986,464; 948,980; 885,191; 710,861; and German Pat. No. 453,483.
The majority of these prior devices use pivotable elements, sometimes biased with springs, to permit the spindle to be moved longitudinally without rotatably threading the spindle through the threaded portion of the clamp. Other prior art devices use rods or bars, sometimes having gear teeth thereon, which are movable against the workpiece and held in place by a clutch mechanism or some other locking device.
It would be desirable to provide a clamping device with the holding strength and simplicity of a threaded spindle, while providing means for rapid, one-hand adjustment without unduly complicating the manufacturing or use of the clamp, thereby maintaining its economy and simplicity.